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1// SPDX-License-Identifier: GPL-2.0-only
2/* display7seg.c - Driver implementation for the 7-segment display
3 * present on Sun Microsystems CP1400 and CP1500
4 *
5 * Copyright (c) 2000 Eric Brower (ebrower@usa.net)
6 */
7
8#include <linux/device.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/fs.h>
12#include <linux/errno.h>
13#include <linux/major.h>
14#include <linux/miscdevice.h>
15#include <linux/ioport.h> /* request_region */
16#include <linux/slab.h>
17#include <linux/mutex.h>
18#include <linux/of.h>
19#include <linux/platform_device.h>
20#include <linux/atomic.h>
21#include <linux/uaccess.h> /* put_/get_user */
22#include <asm/io.h>
23
24#include <asm/display7seg.h>
25
26#define DRIVER_NAME "d7s"
27#define PFX DRIVER_NAME ": "
28
29static DEFINE_MUTEX(d7s_mutex);
30static int sol_compat = 0; /* Solaris compatibility mode */
31
32/* Solaris compatibility flag -
33 * The Solaris implementation omits support for several
34 * documented driver features (ref Sun doc 806-0180-03).
35 * By default, this module supports the documented driver
36 * abilities, rather than the Solaris implementation:
37 *
38 * 1) Device ALWAYS reverts to OBP-specified FLIPPED mode
39 * upon closure of device or module unload.
40 * 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of
41 * FLIP bit
42 *
43 * If you wish the device to operate as under Solaris,
44 * omitting above features, set this parameter to non-zero.
45 */
46module_param(sol_compat, int, 0);
47MODULE_PARM_DESC(sol_compat,
48 "Disables documented functionality omitted from Solaris driver");
49
50MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
51MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500");
52MODULE_LICENSE("GPL");
53
54struct d7s {
55 void __iomem *regs;
56 bool flipped;
57};
58struct d7s *d7s_device;
59
60/*
61 * Register block address- see header for details
62 * -----------------------------------------
63 * | DP | ALARM | FLIP | 4 | 3 | 2 | 1 | 0 |
64 * -----------------------------------------
65 *
66 * DP - Toggles decimal point on/off
67 * ALARM - Toggles "Alarm" LED green/red
68 * FLIP - Inverts display for upside-down mounted board
69 * bits 0-4 - 7-segment display contents
70 */
71static atomic_t d7s_users = ATOMIC_INIT(0);
72
73static int d7s_open(struct inode *inode, struct file *f)
74{
75 if (D7S_MINOR != iminor(inode))
76 return -ENODEV;
77 atomic_inc(&d7s_users);
78 return 0;
79}
80
81static int d7s_release(struct inode *inode, struct file *f)
82{
83 /* Reset flipped state to OBP default only if
84 * no other users have the device open and we
85 * are not operating in solaris-compat mode
86 */
87 if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
88 struct d7s *p = d7s_device;
89 u8 regval = 0;
90
91 regval = readb(p->regs);
92 if (p->flipped)
93 regval |= D7S_FLIP;
94 else
95 regval &= ~D7S_FLIP;
96 writeb(regval, p->regs);
97 }
98
99 return 0;
100}
101
102static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
103{
104 struct d7s *p = d7s_device;
105 u8 regs = readb(p->regs);
106 int error = 0;
107 u8 ireg = 0;
108
109 if (D7S_MINOR != iminor(file_inode(file)))
110 return -ENODEV;
111
112 mutex_lock(&d7s_mutex);
113 switch (cmd) {
114 case D7SIOCWR:
115 /* assign device register values we mask-out D7S_FLIP
116 * if in sol_compat mode
117 */
118 if (get_user(ireg, (int __user *) arg)) {
119 error = -EFAULT;
120 break;
121 }
122 if (sol_compat) {
123 if (regs & D7S_FLIP)
124 ireg |= D7S_FLIP;
125 else
126 ireg &= ~D7S_FLIP;
127 }
128 writeb(ireg, p->regs);
129 break;
130
131 case D7SIOCRD:
132 /* retrieve device register values
133 * NOTE: Solaris implementation returns D7S_FLIP bit
134 * as toggled by user, even though it does not honor it.
135 * This driver will not misinform you about the state
136 * of your hardware while in sol_compat mode
137 */
138 if (put_user(regs, (int __user *) arg)) {
139 error = -EFAULT;
140 break;
141 }
142 break;
143
144 case D7SIOCTM:
145 /* toggle device mode-- flip display orientation */
146 regs ^= D7S_FLIP;
147 writeb(regs, p->regs);
148 break;
149 }
150 mutex_unlock(&d7s_mutex);
151
152 return error;
153}
154
155static const struct file_operations d7s_fops = {
156 .owner = THIS_MODULE,
157 .unlocked_ioctl = d7s_ioctl,
158 .compat_ioctl = compat_ptr_ioctl,
159 .open = d7s_open,
160 .release = d7s_release,
161 .llseek = noop_llseek,
162};
163
164static struct miscdevice d7s_miscdev = {
165 .minor = D7S_MINOR,
166 .name = DRIVER_NAME,
167 .fops = &d7s_fops
168};
169
170static int d7s_probe(struct platform_device *op)
171{
172 struct device_node *opts;
173 int err = -EINVAL;
174 struct d7s *p;
175 u8 regs;
176
177 if (d7s_device)
178 goto out;
179
180 p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL);
181 err = -ENOMEM;
182 if (!p)
183 goto out;
184
185 p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s");
186 if (!p->regs) {
187 printk(KERN_ERR PFX "Cannot map chip registers\n");
188 goto out;
189 }
190
191 err = misc_register(&d7s_miscdev);
192 if (err) {
193 printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n",
194 D7S_MINOR);
195 goto out_iounmap;
196 }
197
198 /* OBP option "d7s-flipped?" is honored as default for the
199 * device, and reset default when detached
200 */
201 regs = readb(p->regs);
202 opts = of_find_node_by_path("/options");
203 if (opts)
204 p->flipped = of_property_read_bool(opts, "d7s-flipped?");
205
206 if (p->flipped)
207 regs |= D7S_FLIP;
208 else
209 regs &= ~D7S_FLIP;
210
211 writeb(regs, p->regs);
212
213 printk(KERN_INFO PFX "7-Segment Display%pOF at [%s:0x%llx] %s\n",
214 op->dev.of_node,
215 (regs & D7S_FLIP) ? " (FLIPPED)" : "",
216 op->resource[0].start,
217 sol_compat ? "in sol_compat mode" : "");
218
219 dev_set_drvdata(&op->dev, p);
220 d7s_device = p;
221 err = 0;
222 of_node_put(opts);
223
224out:
225 return err;
226
227out_iounmap:
228 of_iounmap(&op->resource[0], p->regs, sizeof(u8));
229 goto out;
230}
231
232static int d7s_remove(struct platform_device *op)
233{
234 struct d7s *p = dev_get_drvdata(&op->dev);
235 u8 regs = readb(p->regs);
236
237 /* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
238 if (sol_compat) {
239 if (p->flipped)
240 regs |= D7S_FLIP;
241 else
242 regs &= ~D7S_FLIP;
243 writeb(regs, p->regs);
244 }
245
246 misc_deregister(&d7s_miscdev);
247 of_iounmap(&op->resource[0], p->regs, sizeof(u8));
248
249 return 0;
250}
251
252static const struct of_device_id d7s_match[] = {
253 {
254 .name = "display7seg",
255 },
256 {},
257};
258MODULE_DEVICE_TABLE(of, d7s_match);
259
260static struct platform_driver d7s_driver = {
261 .driver = {
262 .name = DRIVER_NAME,
263 .of_match_table = d7s_match,
264 },
265 .probe = d7s_probe,
266 .remove = d7s_remove,
267};
268
269module_platform_driver(d7s_driver);
1/* display7seg.c - Driver implementation for the 7-segment display
2 * present on Sun Microsystems CP1400 and CP1500
3 *
4 * Copyright (c) 2000 Eric Brower (ebrower@usa.net)
5 */
6
7#include <linux/device.h>
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/fs.h>
11#include <linux/errno.h>
12#include <linux/major.h>
13#include <linux/miscdevice.h>
14#include <linux/ioport.h> /* request_region */
15#include <linux/slab.h>
16#include <linux/mutex.h>
17#include <linux/of.h>
18#include <linux/of_device.h>
19#include <linux/atomic.h>
20#include <asm/uaccess.h> /* put_/get_user */
21#include <asm/io.h>
22
23#include <asm/display7seg.h>
24
25#define D7S_MINOR 193
26#define DRIVER_NAME "d7s"
27#define PFX DRIVER_NAME ": "
28
29static DEFINE_MUTEX(d7s_mutex);
30static int sol_compat = 0; /* Solaris compatibility mode */
31
32/* Solaris compatibility flag -
33 * The Solaris implementation omits support for several
34 * documented driver features (ref Sun doc 806-0180-03).
35 * By default, this module supports the documented driver
36 * abilities, rather than the Solaris implementation:
37 *
38 * 1) Device ALWAYS reverts to OBP-specified FLIPPED mode
39 * upon closure of device or module unload.
40 * 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of
41 * FLIP bit
42 *
43 * If you wish the device to operate as under Solaris,
44 * omitting above features, set this parameter to non-zero.
45 */
46module_param(sol_compat, int, 0);
47MODULE_PARM_DESC(sol_compat,
48 "Disables documented functionality omitted from Solaris driver");
49
50MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
51MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500");
52MODULE_LICENSE("GPL");
53MODULE_SUPPORTED_DEVICE("d7s");
54
55struct d7s {
56 void __iomem *regs;
57 bool flipped;
58};
59struct d7s *d7s_device;
60
61/*
62 * Register block address- see header for details
63 * -----------------------------------------
64 * | DP | ALARM | FLIP | 4 | 3 | 2 | 1 | 0 |
65 * -----------------------------------------
66 *
67 * DP - Toggles decimal point on/off
68 * ALARM - Toggles "Alarm" LED green/red
69 * FLIP - Inverts display for upside-down mounted board
70 * bits 0-4 - 7-segment display contents
71 */
72static atomic_t d7s_users = ATOMIC_INIT(0);
73
74static int d7s_open(struct inode *inode, struct file *f)
75{
76 if (D7S_MINOR != iminor(inode))
77 return -ENODEV;
78 atomic_inc(&d7s_users);
79 return 0;
80}
81
82static int d7s_release(struct inode *inode, struct file *f)
83{
84 /* Reset flipped state to OBP default only if
85 * no other users have the device open and we
86 * are not operating in solaris-compat mode
87 */
88 if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
89 struct d7s *p = d7s_device;
90 u8 regval = 0;
91
92 regval = readb(p->regs);
93 if (p->flipped)
94 regval |= D7S_FLIP;
95 else
96 regval &= ~D7S_FLIP;
97 writeb(regval, p->regs);
98 }
99
100 return 0;
101}
102
103static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
104{
105 struct d7s *p = d7s_device;
106 u8 regs = readb(p->regs);
107 int error = 0;
108 u8 ireg = 0;
109
110 if (D7S_MINOR != iminor(file_inode(file)))
111 return -ENODEV;
112
113 mutex_lock(&d7s_mutex);
114 switch (cmd) {
115 case D7SIOCWR:
116 /* assign device register values we mask-out D7S_FLIP
117 * if in sol_compat mode
118 */
119 if (get_user(ireg, (int __user *) arg)) {
120 error = -EFAULT;
121 break;
122 }
123 if (sol_compat) {
124 if (regs & D7S_FLIP)
125 ireg |= D7S_FLIP;
126 else
127 ireg &= ~D7S_FLIP;
128 }
129 writeb(ireg, p->regs);
130 break;
131
132 case D7SIOCRD:
133 /* retrieve device register values
134 * NOTE: Solaris implementation returns D7S_FLIP bit
135 * as toggled by user, even though it does not honor it.
136 * This driver will not misinform you about the state
137 * of your hardware while in sol_compat mode
138 */
139 if (put_user(regs, (int __user *) arg)) {
140 error = -EFAULT;
141 break;
142 }
143 break;
144
145 case D7SIOCTM:
146 /* toggle device mode-- flip display orientation */
147 regs ^= D7S_FLIP;
148 writeb(regs, p->regs);
149 break;
150 }
151 mutex_unlock(&d7s_mutex);
152
153 return error;
154}
155
156static const struct file_operations d7s_fops = {
157 .owner = THIS_MODULE,
158 .unlocked_ioctl = d7s_ioctl,
159 .compat_ioctl = d7s_ioctl,
160 .open = d7s_open,
161 .release = d7s_release,
162 .llseek = noop_llseek,
163};
164
165static struct miscdevice d7s_miscdev = {
166 .minor = D7S_MINOR,
167 .name = DRIVER_NAME,
168 .fops = &d7s_fops
169};
170
171static int d7s_probe(struct platform_device *op)
172{
173 struct device_node *opts;
174 int err = -EINVAL;
175 struct d7s *p;
176 u8 regs;
177
178 if (d7s_device)
179 goto out;
180
181 p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL);
182 err = -ENOMEM;
183 if (!p)
184 goto out;
185
186 p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s");
187 if (!p->regs) {
188 printk(KERN_ERR PFX "Cannot map chip registers\n");
189 goto out_free;
190 }
191
192 err = misc_register(&d7s_miscdev);
193 if (err) {
194 printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n",
195 D7S_MINOR);
196 goto out_iounmap;
197 }
198
199 /* OBP option "d7s-flipped?" is honored as default for the
200 * device, and reset default when detached
201 */
202 regs = readb(p->regs);
203 opts = of_find_node_by_path("/options");
204 if (opts &&
205 of_get_property(opts, "d7s-flipped?", NULL))
206 p->flipped = true;
207
208 if (p->flipped)
209 regs |= D7S_FLIP;
210 else
211 regs &= ~D7S_FLIP;
212
213 writeb(regs, p->regs);
214
215 printk(KERN_INFO PFX "7-Segment Display%s at [%s:0x%llx] %s\n",
216 op->dev.of_node->full_name,
217 (regs & D7S_FLIP) ? " (FLIPPED)" : "",
218 op->resource[0].start,
219 sol_compat ? "in sol_compat mode" : "");
220
221 dev_set_drvdata(&op->dev, p);
222 d7s_device = p;
223 err = 0;
224
225out:
226 return err;
227
228out_iounmap:
229 of_iounmap(&op->resource[0], p->regs, sizeof(u8));
230
231out_free:
232 goto out;
233}
234
235static int d7s_remove(struct platform_device *op)
236{
237 struct d7s *p = dev_get_drvdata(&op->dev);
238 u8 regs = readb(p->regs);
239
240 /* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
241 if (sol_compat) {
242 if (p->flipped)
243 regs |= D7S_FLIP;
244 else
245 regs &= ~D7S_FLIP;
246 writeb(regs, p->regs);
247 }
248
249 misc_deregister(&d7s_miscdev);
250 of_iounmap(&op->resource[0], p->regs, sizeof(u8));
251
252 return 0;
253}
254
255static const struct of_device_id d7s_match[] = {
256 {
257 .name = "display7seg",
258 },
259 {},
260};
261MODULE_DEVICE_TABLE(of, d7s_match);
262
263static struct platform_driver d7s_driver = {
264 .driver = {
265 .name = DRIVER_NAME,
266 .of_match_table = d7s_match,
267 },
268 .probe = d7s_probe,
269 .remove = d7s_remove,
270};
271
272module_platform_driver(d7s_driver);